I was thinking they would be insect like in appearance, multiple limbs, exoskeleton, large mandibles. They would be fairly large, and very varied, like insects in real life. Drones, A queen, hunters, gatherer's, things like that. Insects are some of the most varied and numerous creatures, it makes sense that they could possibly rule a planet and start taking over XD
Yeah, I was thinking the dogs would be very large, they would need to be in order to fight the aliens, which would be pretty big in my opinion (perhaps that size from some genetic material from a bear or a big cat XD)